Id is both a technology and an art company, so we try to push the art and the technology to its edge on each game, and when you're into high-tech you want to make sure your game can run on several platforms, and you have some room to experiment with several architectures. We don't want to have a basic product, get it out the door, sell as many copies as we can, and then just do the next one. Everyone's putting a lot of soul into the games, and id has got enough money overhead to decide that they can afford to have game ports to show that technology is good on Linux and on Apple hardware.